The present invention relates to a needle assembly. More particularly, the invention relates to contact and penetration depth sensor for such a needle assembly.
There are many medical circumstances in which an increase in the supply of blood to living tissue is desirable. These include: burns and wound healing, in which the incorporation of angiogenic factors into artificial skin may facilitate the formation of blood vessels in the healing wound and reduce the risk of infection; cardiovascular disease, in which repair of anginal or ischemic cardiac tissue may be enhanced by causing the ingrowth of new blood vessels; stroke, where increased blood supply to the brain may reduce the risk of transient ischemic attack and/or cerebral arterial deficiency; and peripheral vascular disease, in which blood flow in the extremities is increased through the formation of new vessels. In each case, the growth of new blood vessels may increase the volume of blood circulating through the tissue in question, and correspondingly may increase the amount of oxygen and nutrients available to that tissue. However, some individuals are unable to generate sufficient collateral vessels to adequately increase the volume of blood through the tissue.